A071752 Expansion of (1+x^4*C^3)*C^3, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.

1, 3, 9, 28, 91, 303, 1028, 3542, 12363, 43628, 155414, 558144, 2018750, 7347281, 26888610, 98888730, 365292555, 1354757040, 5042499990, 18830130360, 70527871530, 264886906830, 997372693824, 3764155637772, 14236915323806

Offset

0,2

Links

Table of n, a(n) for n=0..24.

Mathematica

c = (1 - (1 - 4*x)^(1/2))/(2*x); (1 + x^4*c^3)*c^3 + O[x]^25 // CoefficientList[#, x]& (* Jean-François Alcover, Sep 27 2017 *)

Crossrefs

Sequence in context: A047047 A071744 A071748 * A071756 A176673 A215007

Adjacent sequences: A071749 A071750 A071751 * A071753 A071754 A071755

Keyword

nonn

Author

N. J. A. Sloane, Jun 06 2002

Status

approved